Known joints utilized in fluid ducts, under low or medium pressures, such as hydraulic and pneumatic systems are locked into valves, crank, cylinder or air or oil pumps, etc. and are equipped with rotatable joints with male or female screw threads.
In order to lock a rotating joint body to a main joint body, a ring groove is applied around a projection of the rotating joint body and another groove, this one in the internal face of the main joint body, is locked, by fitting a metallic locking ring.
This manufacturing process, well known and amply utilized, requires two stages of machine-made rings, one externally, around the projection of the rotating joint body and which will be inserted in the main body and, one internally, in the main body, aligned for locking by the mentioned metallic locking ring, the imperviousness between these two parts being assured by an O-ring.
Thus, it is noticeable that a very complex manufacturing process is required, requiring micro-metric precision to guarantee perfect alignment and imperviousness and consequent security, factors that are fundamental if one considers where these joints will be used. This complexity necessarily entails a prolonged manufacturing process, which is expensive and involves many components.